Universal Detection of Ions by Replacement-Ion Chromatography Employing an Anion-Replacement Method and an Ultraviolet-Visible Spectrophotometric Detector

摘要

A new ion-chromatographic (IC) detection method involving replacement-ion chromatography (RIC) and an anion-replacement arrangement is employed for cation and anion analysis. In the instrument, a conventional dual-column IC system is followed by a continuously regenerated anion-exchange (ionomeric) fiber, which serves as the replacement column. This third column converts all ionic solutes into their iodate or nitrate salts, which are detected sensitively at 215 nm by a UV-visible spectrophotometer. This detection method is especially useful for cation separation, for which the influence of various system parameters are discussed in detail. Good precision (RSD<5%), low detection limits (1-15 ng), and universal calibration were achieved for several monovalent cations. However, the method does not appear to be useful for anion determinations.